Recently, an increased proportion of caskets are contained within crypts in above-ground mausoleums. It has been found that the metal casket is prone to deterioration through corrosion by organic acids contained within the casket as well as by oxidative corrosion. The oxidation of formaldehyde used in the embalming fluid generates formic acid, and the decomposition of the human remains also generates other organic acids which will attack and corrode the metal casket, resulting in the destruction of the casket and leakage of the acidic components. The leakage of the acid from the casket can stain, discolor and damage the marble crypts.
As an additional problem, the putrification of the human remaains in the casket due to microbial growth can cause undesirable odors in the crypt and mausoleum.
Attempts have been made in the past to prevent the corrosion of metal caskets by the application of various types of coatings such as asphalt, amine salts, polyurethane form and the like. However, coatings of this type have not been satisfactory in combating acidic corrosion caused by the organic acids.
U.S. Pat. No. 4,520,043 is directed to an improved coating composition for a metal casket in which the coating comprises a resin or rubber matrix containing finely divided dispersed particles of an alkaline material, such as a metal carbonate or bicarbonate. The ingredients of the coating composition are mixed with an evaporable carrier, such as water, and applied to the interior surface of the casket. On evaporation of the carrier, a thin moisture-permeable coating results. As the organic acids permeate through the coating, the acids will be neutralized by the alkaline material contained within the coating to thereby prevent acidic corrosion of the metal casket.